Impact of beneficiary status on bariatric surgery outcomes in a military treatment facility

Abstract Background Retirees and dependents represent demographically and clinically distinct beneficiary groups within the Military Health System (MHS). We assessed whether beneficiary status influences perioperative outcomes, healthcare utilization, and weight loss after bariatric surgery. Methods We conducted a retrospective cohort study of adults undergoing sleeve gastrectomy or Roux-en-Y gastric bypass from 01/01/2022 to 12/31/2024 at a single military treatment facility. Outcomes were stratified by beneficiary status (retiree versus dependent). Propensity scores incorporating demographic, clinical, and procedural factors were used to construct overlap weights, yielding covariate balance comparable to randomized allocation. Overlap-weighted logistic and linear regression models assessed the independent association between beneficiary status and postoperative outcomes. Sex interaction terms evaluated effect modification. A female-only 1:1 propensity score-matched analysis served as a sensitivity analysis to address marked sex imbalance between groups. Results Among 281 patients, 123 (43.8%) were retirees and 158 (56.2%) dependents. Retirees were older (median 50 versus 46 years, p = 0.003), predominantly male (52% versus 7%, p < 0.001), higher frequency Black (12.2% versus 5.1%, p = 0.052) and Hispanic (22.8% versus 11.4%, p = 0.017) and had higher comorbidity burden (median count 5.0 versus 4.0, p < 0.001). Revision/conversion procedures were less common in retirees; otherwise, operative indices were comparable. In unadjusted analyses, retirees had shorter hospital length of stay (LOS), fewer all-cause ED visits at 30 days, and fewer surgical ED visits through 12 months. However, in weighted regression, beneficiary status was not independently associated with LOS, ED visits, readmissions, or short-term percent total weight loss. No significant sex–beneficiary status interaction was observed. In the female-only matched cohort ( N = 114; 57 pairs), outcomes again remained comparable. Conclusions After covariate adjustment using overlap weighting and sex-restricted propensity matching, beneficiary status was not independently associated with LOS, postoperative healthcare utilization, or short-term weight loss. These findings suggest equitable bariatric outcomes across MHS beneficiary groups. Graphical abstract